JPH0679892B2 - Deceleration response type braking compensator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a braking correction device that responds to deceleration of a vehicle.

When the vehicle is being braked, particularly the rear wheels tend to lock due to the reduction of the load, so it is desirable to limit the brake pressure of the rear wheels to the brake pressure of the front wheels above a predetermined critical value of deceleration.

French patent application No. 84 / 17,728 has a deceleration responsive braking compensator that is slidably mounted inside and that has a mass that responds to the deceleration of the vehicle and closes the valve for controlling the brake circuit. Have been described. The braking compensator also includes a piston that is biased by a spring having a predetermined set force to prevent the mass from moving and closing the valve before the critical value of deceleration reaches a predetermined level.

This conventional braking compensator has the advantage that when the critical value of deceleration exceeds a certain level, the piston is separated from the mass but the mass is completely submerged in the fluid. Therefore, it is impossible to move the valve to close the valve immediately due to the fluid friction, and there is a drawback that the response time until the brake pressure of the wheel is limited after closing the valve is too long.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a deceleration-responsive braking compensator which eliminates the drawbacks of the conventional device and improves the response time.

To this end, the invention provides a body having a chamber, an inlet connected to the chamber and to a source of pressurized fluid, and an outlet connected to the chamber and to a vehicle brake. In the included deceleration response type braking correction device,
A mass that is slidably mounted in the room and responds to the deceleration of the vehicle, a piston that presses the mass toward the rest position and forms a closing element for the on-off valve, and bypasses the on-off valve to reduce the deceleration. A bypass means having a throttle that is sealed by the mass when the mass moves accordingly is provided, and the closing of the on-off valve and the sealing of the throttle occur successively.

According to this configuration, at a predetermined pressure value, the piston separates from the mass to close the on-off valve, and then at the predetermined critical value of deceleration, the mass moves to seal the throttle of the bypass means, The brake pressure of the rear wheels can be sequentially limited to improve the response time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the first embodiment of the present invention shown in FIGS. 1 to 5, the deceleration-responsive braking compensator comprises three stepped holes 12, 14 and 1.
Includes body 10 with 6. Casing 18 is body 1
It is fixed at 0 and forms a chamber 20 with the body. The first stepped hole 12 is a threaded inlet orifice that is connected to a pressurized fluid generator (not shown), such as master chilling.
22 are provided. At the other end of the stepped hole 12, an axial member 24 having a longitudinal hole 26 connected to a lateral hole 28 is fixed. An annular mass 30 is slidably mounted on the axial member 24 by a ball bearing 32. Annular mass 30
Has a first position relative to the stop 34 by means of a return spring 36, one end of which is attached to the axial member 24 via an adjusting screw 38.
It is normally held in the rest position shown.

The second stepped hole 14 has an exit orifice 40 which is connected to a rear wheel brake (not shown) of the vehicle. The valve seat 42 that constitutes the bypass means is attached to the other end of the stepped hole 14,
It has a throttle or small diameter longitudinal bore 44 connecting 14 to the chamber 20. The valve seat 42 has a seal ring 46 that cooperates with the annular mass 30 to close the longitudinal bore 44 when the annular mass 30 abuts the valve seat 42, as described below.

The third stepped hole 16 has a stepped piston including a head portion 50 having a seal ring 52 constituting an on-off valve and a small diameter portion 54.
Has 48. The stepped piston 48 is pressed to the left in the figure by the spring 56, and the setting force of the spring 56 can be adjusted by the screw 58. Two stepped holes 14 and 16
Are connected to each other by a gutter 60.

The braking compensator is mounted on the vehicle such that its longitudinal axis is parallel to the longitudinal axis of the vehicle and the casing 18 faces rearward.

The braking correction device described above operates as follows.

During the first braking phase, while the deceleration and the pressure in the chamber 20 are smaller than a predetermined critical value, the combined action of the stepped piston 48 and the return spring 36 causes the annular mass 30 to remain stationary with respect to the stop. Kept in. As shown in FIG. 3, the fluid flows from the master cylinder to the stepped hole 12, the side groove 60 and the stepped hole 14.
And then distributed to the rear wheel brakes of the vehicle. Due to the difference in channel resistance, the fluid will flow through the gutter 60 rather than through the restriction or longitudinal bore 44. The pressure in chamber 20 increases,
It acts on the surface of the stepped piston 48.

When the pressure in the chamber 20 suddenly rises above a predetermined critical value, the stepped piston 48 is moved to the right and abuts the body 10 of the braking compensator, as shown in FIG. In this position, the seal ring 52, which constitutes the on-off valve, closes the side groove 60. The only passages through which the fluid can flow is a restriction or small diameter longitudinal bore 44. Therefore, the increase in pressure on the rear wheel brakes will be limited by the longitudinal holes 44.

FIG. 5 shows the operating position of the braking compensator when the deceleration and the pressure in the chamber 20 exceed a critical value. The annular mass 30 is moved to the right and abuts the sealing ring 46 on the valve seat 42 which constitutes the bypass means and closes the longitudinal bore 44. Therefore, the passage leading to the rear wheel brake is completely closed and the pressure in the rear wheel brake is kept constant.

6 to 8 show the valve seat 42 and the stepped piston 48,
A second embodiment of the present invention is shown in which a single valve device 61 slidably fitted in the hole 63 is replaced. The valve device 61 includes a stepped piston 48 that is pressed to the left by an adjustment spring 64.
Includes piston 62 similar to. The valve device 61 also has a valve 66 with a throttle or small bore 68 and two sealing rings 70,71.

FIG. 6 shows the braking compensator in the rest position, in which the braking compensator is kept in this position as long as the deceleration and the pressure in the chamber 20 are below a certain critical value. Due to the combined action of the return spring 36 and the adjusting spring 64 of the valve device 61, the annular mass 30 is kept stationary. Therefore, the fluid can freely flow from the master cylinder through the stepped hole 12 and the hole 72 to the rear brake of the vehicle.

When the pressure in the chamber 20 suddenly rises above a predetermined critical value, the valve device 61 moves to the right as shown in FIG. 7,
The seal ring 70 that constitutes the on-off valve contacts the body 10 of the control correction device. In this position, the only passages through which the fluid can flow are the throttling or small diameter holes 68. Therefore, the increase in pressure on the rear wheel brakes is limited by the holes 68.

When the pressure and deceleration exceed a predetermined critical value, the annular mass 30 moves to the right and abuts the seal ring 71 of the valve 66 forming the bypass means, as shown in FIG.
Therefore, the hole 68 is closed, and the pressure of the rear wheel brake is kept constant.

[Brief description of drawings]

1 and 2 are longitudinal sectional views showing the braking compensator according to the present invention at different sectional positions, and FIGS. 3 to 5 show the braking compensator according to the first embodiment of the present invention at different operating positions. FIG. 6 is a sectional view of a main part, and FIGS. 6 to 8 are sectional views of a main part showing a braking correction device according to a second embodiment of the present invention in different operating positions. 10 …… body, 12,14,16 …… stepped hole, 18 …… casing, 20 …… chamber, 22 …… inlet orifice, 30 …… annular mass, 40 …… outlet orifice, 42 …… valve seat ( Bypass means), 44 ... longitudinal hole (throttle), 48 ... stepped piston, 52 ... seal ring (open / close valve), 61 ... valve device, 62
...... Piston, 66 ... Valve (bypass means), 68 ... Hole (throttle), 70 ... Seal ring (open / close valve).

Claims (3)

[Claims] 1. A body (10) having a chamber (20) and a chamber (2).
0) and an inlet (2
2) and an outlet (40) that is connected to the room (20) and is connected to the vehicle brake, and is slidably mounted in the room (20) and responds to the deceleration of the vehicle. Mass (30) and a piston (4) that presses the mass (30) towards a rest position to form a closing element for the on-off valve (52; 70).
8; 62) and a bypass means (42; 66) that bypasses the on-off valve (52; 70) and has a throttle (44; 68) that is sealed by the mass (30) when the mass (30) moves in response to deceleration. ) And the closing of the on-off valve (52; 70) and the sealing of the throttle (44; 68) are connected to each other so as to occur. 2. An on-off valve (52; 70) and a bypass means (42; 66).
Are arranged in parallel with each other, and the braking correction device according to claim 1 characterized in that. 3. An on-off valve (52; 70) and a bypass means (42; 66).
Are arranged coaxially with each other, and the braking correction device according to claim 2 is characterized in that.